I can write you can write he can write we can write you can write they can write
V-ing form
I can be writing you can be writing he can be writing we can be writing you can be writing they can be writing
Perfect
I can have written you can have written he can have written we can have written you can have written they can have written
V-ing perfect
I can have been writing you can have been writing he can have been writing we can have been writing you can have been writing they can have been writing
Negation
Simple form
I cannot write you cannot write he cannot write we cannot write you cannot write they cannot write
V-ing form
I cannot be writing you cannot be writing he cannot be writing we cannot be writing you cannot be writing they cannot be writing
Perfect
I cannot have written you cannot have written he cannot have written we cannot have written you cannot have written they cannot have written
V-ing perfect
I cannot have been writing you cannot have been writing he cannot have been writing we cannot have been writing you cannot have been writing they cannot have been writing
Interrogative form
Simple form
can I write? can you write? can he write? can we write? can you write? can they write?
V-ing form
can I be writing? can you be writing? can he be writing? can we be writing? can you be writing? can they be writing?
Perfect
can I have written? can you have written? can he have written? can we have written? can you have written? can they have written?
V-ing perfect
can I have been writing? can you have been writing? can he have been writing? can we have been writing? can you have been writing? can they have been writing?
Interro-negative form
Simple form
can I not write? can you not write? can he not write? can we not write? can you not write? can they not write?
V-ing form
can I not be writing? can you not be writing? can he not be writing? can we not be writing? can you not be writing? can they not be writing?
Perfect
can I not have written? can you not have written? can he not have written? can we not have written? can you not have written? can they not have written?
V-ing perfect
can I not have been writing? can you not have been writing? can he not have been writing? can we not have been writing? can you not have been writing? can they not have been writing?